Relationship Testing

Which of our tests is the right one for you? Please select a category below to discover...

Twin Zygosity DNA Testing

This DNA test determines whether siblings are fraternal or identical twins or siblings. The cost of the DNA testing service includes two children but you may add more as needed; for instance a third sibling. Parental samples are optional; if provided, paternity and/or maternity can also be verified.

Step One: Review Shipping Information

Please review the following important information:

All orders are shipped in plain, confidential packaging. There is nothing on our return address or packages to indicate the nature of the product inside!

For shipping in the Contiguous U.S.

* All orders, shipping within the Contiguous USA, include a pre-paid return mailer based on your selected shipping method for NO EXTRA CHARGE
* You may choose how you want your kit sent to you. US Mail will take approximately 7-15 business days. For faster delivery of your kit, you may choose Priority Mail, UPS overnight or our FedEx options (both UPS and FedEx require a street address and telephone number)

For shipping outside of the Contiguous U.S:

Orders to Canada, Mexico, Hawaii, Alaska, Puerto Rico and recognized US territories can be shipped by US Mail, UPS or FedEx (additional international fees apply for UPS and FedEx delivery) but may not contain a prepaid return package. For INTERNATIONAL orders please call or e-mail for shipping and handling charges.

When orders are shipped:

Orders received* Monday through Thursday by 12 noon Mountain Time will be shipped that day; if you choose UPS or FedEx overnight you will receive the paternity test kit the following day. Orders placed on Fridays for UPS or FedEx overnight shipment will arrive Monday. Please call to see if FedEx Saturday is available in your area before placing an order. GTL does not ship or receive on weekends and most federal holidays.

Multiple locations:

You may order additional kits, which will include prepaid returns based on your selected method of shipping (for use in the Contiguous United States only). Additional kits are $30 for informational and $40 for legally binding. To order additional kits, please call GTL Toll-Free at (866) 833-6895.

* Although you may place your order before noon, GTL may not receive the order notification for several hours.

Step Two: Select a DNA Test

Please Note: All orders, shipping within the Contiguous USA, include a pre-paid return via your selected method of shipping.

Informational DNA Test

The cost of the twin zygosity test service includes two children but you may add more as needed; for instance a third sibling. Parental samples are optional; if provided, paternity and/or maternity can also be verified.

Buccal Swabs or Blood Samples? Read More
Will one or both parents also be tested?
Additional Children?
Add optional rush analysis: Full explanation of rush analysis can be found below. Read More
Would you like professional collection services? Learn more about professional collection and our extensive network of collection facilities. Read More
Shipping Method (we strongly recommend you choose to ship via a trackable carrier, such as UPS or FedEx. We cannot track US Mail or Priority Mail.): Read More

Legally Binding DNA Test

If you believe you'll need your test results to be legally binding, you'll need the Legally Binding Test. Click here to learn more about this type of twin zygosity test. type

Buccal Swabs or Blood Samples? Read More
Will one or both parents also be tested?
Additional Children?
Add optional rush analysis: Full explanation of rush analysis can be found below. Read More
Would you like professional collection services? Learn more about professional collection and our extensive network of collection facilities. Read More
Shipping Method (we strongly recommend you choose to ship via a trackable carrier, such as UPS or FedEx. We cannot track US Mail or Priority Mail.): Read More
Please select "I agree" if you have read and agree to the GTL Legal Test Agreement:

I agree to the GTL Legal Test Agreement

Review Additional Information

Information concerning how samples are taken, the difference between legal and informational testing, buccal versus "pin-prick" sample collection, and more is available and should be reviewed. Find out more about the requirements of legal paternity testing.

Helpful Links

* Finding the answers is important. Discover the benefits of our paternity testing services.

Our Refund Policy

DNA test samples must be submitted within one-year of case initiation or the case will be closed. Refunds for DNA or paternity test kits, Internet specials, and International orders will not be issued: all sales are final. Full details on our refund policy can be found here.

Rush Analysis Options

24-Hour Release: $400

No more than 24 business hours from receipt of samples
Next Day Release: $175

By close of business on next business day following receipt of samples
Second Day Release: $125

By close of business on 2nd business day following receipt of samples
Third Day Release: $75

By close of business on 3rd business day following receipt of samples

Select a DNA Test

Discover the many DNA test options available from GTL.

Quality is Assured

Click here to see a list of our accreditations and affiliations
Satisfaction Guaranteed

Click here to read selected testimonials about our services and products
How Do the Tests Work?

Click here to read easy-to-understand instructions about our tests

Relationship Testing

Which of our tests is the right one for you? Please select a category below to discover...